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J Matsuda

Publications and source records attributed to J Matsuda.

At least 19 recordsLinked to original sources
PubMed2001

Dramatic phenotypic improvement during pregnancy in a genetic leukodystrophy: estrogen appears to be a critical factor.

Globoid cell leukodystrophy is one of the classical genetic leukodystrophies in humans. The typical infantile disease in man (Krabbe disease) is caused by deficiency of lysosomal galactosylceramidase. We recently generated a new mouse model of a late-onset, chronic form of the disease by inactivating saposin A, the essential activator of galactosylceramidase. The phenotypic features of saposin A(-/-) mice are qualitatively identical but milder than those of twitcher mice, which is caused by genetic galactosylceramidase deficiency. During intercrossing of saposin A(-/-) mice, we observed that affected females that are continually pregnant showed greatly improved neurological symptoms compared to affected females that do not experience pregnancy, or affected males. The pathological hallmark of globoid cell leukodystrophy, demyelination with infiltration of globoid cells, largely disappeared. The immune-related gene expression (MCP-1, TNF-alpha) was significantly down-regulated in the brain of pregnant saposin A(-/-) mice. In addition, we found intense expression of the estrogen receptors (ER alpha and ER beta) on the globoid cells, activated astrocytes and microglia in the demyelinating area of saposin A(-/-) mice. When saposin A(-/-) mice were subcutaneously implanted with time-release 17 beta-estradiol (E2) pellets from 30 to 90 days, the pathology was vastly improved. These findings suggest that a higher level of estrogen during pregnancy is one of the important factors in the protective effect of pregnancy. While we should be cautious in extrapolating these observations in the mouse to human disease, the phenomenon is spectacularly dramatic and estrogen administration might be worth a consideration as a supplementary treatment for some chronic genetic leukodystrophies.

Animals↗
PubMed2001

Requirement for C3G-dependent Rap1 activation for cell adhesion and embryogenesis.

C3G is a guanine nucleotide exchange factor (GEF) for Rap1, and is activated via Crk adaptor protein. To understand the physiological role of C3G, we generated C3G knockout mice. C3G(-/-) homozygous mice died before embryonic day 7.5. The lethality was rescued by the expression of the human C3G transgene, which could be excised upon the expression of Cre recombinase. From the embryo of this mouse, we prepared fibroblast cell lines, MEF-hC3G. Expression of Cre abolished the expression of C3G in MEF-hC3G and inhibited cell adhesion-induced activation of Rap1. The Cre-expressing MEF-hC3G showed impaired cell adhesion, delayed cell spreading and accelerated cell migration. The accelerated cell migration was suppressed by the expression of active Rap1, Rap2 and R-Ras. Expression of Epac and CalDAG-GEFI, GEFs for Rap1, also suppressed the accelerated migration of the C3G-deficient cells. This observation indicated that Rap1 activation was sufficient to complement the C3G deficiency. In conclusion, C3G-dependent activation of Rap1 is required for adhesion and spreading of embryonic fibroblasts and for the early embryogenesis of the mouse.

Animals↗
PubMed2001

A mutation in the saposin A domain of the sphingolipid activator protein (prosaposin) gene results in a late-onset, chronic form of globoid cell leukodystrophy in the mouse.

Sphingolipid activator proteins (saposins A, B, C and D) are small homologous glycoproteins derived from a common precursor protein (prosaposin) encoded by a single gene. They are required for in vivo degradation of sphingolipids with short carbohydrate chains. Six cysteines and one glycosylation site are strictly conserved in all four saposins. Total deficiency of all saposins and specific deficiency of saposin B or C are known among human patients. A mouse model of total saposin deficiency closely mimics the human disease. However, no specific saposin A or D deficiency is known. We introduced an amino acid substitution (C106F) into the saposin A domain by the Cre/loxP system which eliminated one of the three conserved disulfide bonds. Saposin A(-/-) mice developed slowly progressive hind leg paralysis with clinical onset at approximately 2.5 months and survival up to 5 months. Tremors and shaking, prominent in other myelin mutants, were not obvious until the terminal stage. Pathology and analytical biochemistry were qualitatively identical to, but generally much milder than, that seen in the typical infantile globoid cell leukodystrophy (GLD) in man (Krabbe disease) and in several other mammalian species, due to genetic deficiency of lysosomal galactosylceramidase (GALC) (EC 3.2.1.46). Thus, saposin A is indispensable for in vivo degradation of galactosylceramide by GALC. It should now be recognized that, in addition to GALC deficiency, genetic saposin A deficiency could also cause chronic GLD. Genetic saposin A deficiency might be anticipated among human patients with undiagnosed late-onset chronic leukodystrophy without GALC deficiency.

Amino Acid Substitution↗
PubMed2001

Galactonojirimycin derivatives restore mutant human beta-galactosidase activities expressed in fibroblasts from enzyme-deficient knockout mouse.

Ten low molecular compounds analogous to galactose were screened for inhibition of human beta-galactosidase activity. Among them, 1-deoxy-galactonojirimycin and N-(n-butyl)-deoxy-galactonojirimycin showed an inhibitory effect at high concentrations. However, they restored mutant enzyme activities expressed in enzyme-deficient knockout mouse fibroblasts and human beta-galactosidosis fibroblasts at lower intracellular concentrations. This effect was more remarkable on G(M1)-gangliosidosis mutations (R201C, I51T, R201H, R457Q) than Morquio B disease mutations (W273L, Y83H). These low molecular compounds pass though the blood-brain barrier in mice. We hope that this new therapeutic approach will become clinically applicable in the near future.

1-Deoxynojirimycin↗
PubMed2001

Development of lysosomal storage in mice with targeted disruption of the beta-galactosidase gene: a model of human G(M1)-gangliosidosis.

A deficiency of lysosomal acid beta-galactosidase leads to G(M1)-gangliosidosis in humans, which progressively and profoundly affects the brain and other organs mainly in the early infantile period. We report the pathology of mice with targeted disruption of the beta-galactosidase gene. In the central nervous system, vacuolated neurons appeared in the spinal cord 3 days after birth. The vacuolation extended to neurons in the brainstem, cerebral cortex, hippocampus and thalamus and ballooning neurons became prominent with age. The vacuolation also appeared in Purkinje cells without a marked ballooning change. Reactive astrogliosis in the entire brain was marked at the terminal stage of the disease. Immunohistochemical study using anti-ganglioside G(M1) and G(A1) antibodies revealed extensive accumulation of G(M1) and G(A1) in the cerebral neurons. In the liver, however, accumulation of G(M1) was localized in the cytoplasm of hepatocytes, whereas that of G(A1) was localized in foamy macrophages and Kupffer cells. There were no significant abnormalities in the bone, bone marrow, or cornea at any stage. Although there are some phenotypic and biochemical differences between this knockout mouse and human GM1 gangliosidosis, the mouse will be a useful model for therapeutic trials for the human disease.

Animals↗
PubMed2001

Psychosine is as potent an inducer of cell death as C6-ceramide in cultured fibroblasts and in MOCH-1 cells.

Cytotoxic capacity of psychosine (galactosylsphingosine) was evaluated in comparison with C6-ceramide in cultured fibroblasts and the glia-derived MOCH-1 cells that have characteristics of myelinating cells (1). Psychosine caused cytotoxic cell death and DNA fragmentation at concentrations similar to C6-ceramide and MOCH-1 cells were substantially more sensitive to their cytotoxic effects than fibroblasts. In this system, pretreatment with GM1-ganglioside failed to protect the cells from the deleterious effects of these compounds. These findings are consistent with the hypothesis that psychosine is the cytotoxic metabolite that causes apoptotic death of the oligodendrocyte in globoid cell leukodystrophy (Krabbe disease). They further suggest that the protective capacity of GM1-ganglioside is unlikely to be the explanation for the paradoxical improvement of the phenotype of globoid cell leukodystrophy in the mouse simultaneously deficient in two lysosomal beta-galactosidases, galactosylceramidase and GM1-ganglioside beta-galactosidase.

Animals↗
PubMed2001

Ala/Thr60 variant of the Leydig insulin-like hormone is not associated with cryptorchidism in the Japanese population.

BACKGROUND: Leydig insulin-like hormone (Insl3), a member of the insulin-like superfamily, is specifically expressed in Leydig cells of fetal and postnatal murine testis. Recently, the absence of the Insl3 gene has been reported to result in bilateral cryptorchidism in male mice and it has been suggested that mutations of the INSL3 gene may cause cryptorchidism in humans. METHODS: We sequenced the INSL3 gene from five Japanese patients with sporadic bilateral cryptorchidism. Patients' genome DNA was prepared from blood leukocytes. Two exons of the INSL3 gene were amplified by polymerase chain reaction and were sequenced directly. A restriction fragment length polymorphism assay was performed on 70 control samples for analysis of polymorphism. RESULTS: Three of five cases had a heterozygous single-base change, a G to A transition at position 178 of the INSL3 gene, which predicts an alanine (GCC) to threonine (ACC) change at codon 60 (designated A60T). However, the A60T mutation was also found in the normal Japanese population at an allele frequency of 26%, which suggests that this mutation is a common polymorphism and is not associated with the occurrence of cryptorchidism. CONCLUSIONS: No mutation has been found in the INSL3 gene from Japanese patients with idiopathic cryptorchidism. We did find the A60T polymorphism, which was not associated with the occurrence of cryptorchidism.

Adolescent↗
PubMed2001

Expression of immune-related molecules is downregulated in twitcher mice following bone marrow transplantation.

Twitcher (twi/twi) is a murine model of a human genetic demyelinating disease, globoid cell leukodystrophy (Krabbe disease). The affected mice usually die before reaching age 45 days, having demyelination associated with extensive glial activation. The twi/twi mice that receive wild-type bone marrow transplantation (BMT) survive up to 3 times longer with improved pathology. We hypothesize that immune-related molecules such as cytokines and chemokines are partly responsible for the demyelination in twi/twi, and that the decrease in the expression of such molecules following BMT contributes to clinico-pathological improvement. Cells expressing TNF-alpha, MCP-1, and MIP-1beta were conspicuous in the twi/twi CNS accompanied by infiltration of Ia+ and CD8+/CD3- hematogenous cells. These cells decreased gradually after BMT TNF-alpha mRNA and mRNA of C-C chemokine families, including MCP-1, IP-10, MIP-1alpha, MIP-1beta, and RANTES, were upregulated in the twi/twi CNS but downregulated gradually following BMT. In twi/twi that survived to 20 wk of age, cells expressing TNF-alpha, MCP-1, MIP-1beta, Ia, or CD8 were hardly detected and pathology was clearly improved. These results are consistent with the hypothesis that cytokine expression in glial cells contributes (to some extent) to the pathogenesis of demyelinating lesions in the twi/twi mice.

Animals↗
PubMed2001

Up-regulation of uncoupling protein 3 gene expression by fatty acids and agonists for PPARs in L6 myotubes.

Uncoupling protein 3 (UCP3), which uncouples electron transport from ATP synthesis, is expressed at high levels in the skeletal muscle, an important organ in glucose and lipid metabolism. Because several reports proposed that fatty acids induced UCP3 gene expression in skeletal muscle in vivo, in the present study we examined the regulation of UCP3 gene expression by various fatty acids using L6 myotubes. UCP3 gene expression was increased in L6 myotubes by various fatty acids or by alpha-bromopalmitate, a nonmetabolized derivative of palmitic acid. Because fatty acids are also known as agonists for PPARs, we examined the involvement of PPARs in the regulation of the UCP3 gene expression. L-165041, a PPAR delta agonist, increased UCP3 gene expression in L6 myotubes, whereas neither Wy 14,643, a PPAR alpha agonist, nor Pioglitazone, a PPAR gamma agonist, increased it. Therefore, we conclude that UCP3 gene expression is increased by the activation of PPAR delta in L6 myotubes and postulate that PPAR delta mediates at least some part of the increased UCP3 gene expression by fatty acids in skeletal muscle in vivo.

Animals↗
PubMed2001

Clinical manifestations of influenza a myocarditis during the influenza epidemic of winter 1998-1999.

OBJECTIVES: The clinical features of myocarditis that developed during the influenza epidemic of winter 1998-1999 were investigated to emphasize the need for medical attention to this disease. METHODS: Nine patients were treated under diagnoses of acute myocarditis during the winter of 1998-1999. Five (two males and three females, mean age 52 +/- 18 years) were examined with myocarditis associated with influenza A. The diagnosis of influenza A myocarditis was based on electrocardiographic and echocardiographic abnormalities, increased creatine kinase levels and at least a four-fold increase in influenza A virus titers using paired sera. RESULTS: All patients had preceding flu-like symptoms and fever. Cardiac involvement developed between 4 and 7 days after the onset of influenza symptoms. Dyspnea progressively worsened in three patients, one went into shock and one had persistent fever, cough and mild dyspnea without apparent cardiac symptoms. Three patients had ST elevation associated with Q waves and one had complete left bundle branch block. The creatine kinase levels were abnormally increased and global wall motion of the left ventricle on echocardiography was decreased in all patients. Two patients had diagnoses of fulminant myocarditis. One patient died of pneumonia following cerebral infarction, but the left ventricular dysfunction normalized in the remaining four patients. CONCLUSIONS: Cardiac involvement occurred between 4 and 7 days after the onset of influenza symptoms, and worsening dyspnea was the most common symptom. Electrocardiography, echocardiography and creatine kinase levels should be checked to determine the potential for cardiac involvement when patients present with suspected influenza associated with worsening dyspnea or prolonged weakness. Increasing the awareness of influenza myocarditis may help in the earlier identification and treatment of this disease during influenza epidemics.

Adult↗
PubMed2001

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1999)].

From October 1999 to September 2000, we collected the specimen from 430 patients with lower respiratory tract infections in 17 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and antibiotics and patients' characteristics. Of 515 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 506 strains were investigated. The breakdown of the isolated bacteria were: Staphylococcus aureus 78, Streptococcus pneumoniae 101, Haemophilus influenzae 104, Pseudomonas aeruginosa (non-mucoid) 58, P. aeruginosa (mucoid) 11, Moraxella subgenus Branhamella catarrhalis 41, Klebsiella pneumoniae 18, etc. Of 78 S. aureus strains, those with 4 micrograms/ml or above of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) occupied 57.7%. Vancomycin and arbekacin showed the most potent activities against MRSA without detection of ABK-resistant strain (MIC: 64 micrograms/ml) and decrease of VCM-sensitive strains those were found in 1998. The frequency of S. pneumoniae exhibiting low sensitivity to penicillin (penicillin-intermediate S. pneumoniae: PISP + penicillin-resistant S. pneumoniae: PRSP) decreased to 34.7% from 46.0% in 1998. The frequency of PRSP was 3.0%, being the least number after 1991. Carbapenems showed strong activities against S. pneumoniae. Especially, panipenem inhibited the growth of all 101 strains with MIC of 0.063 microgram/ml. Generally, all drugs showed strong activities against H. influenzae with MIC80s of 4 micrograms/ml or below. MICs of ofloxacin ranged between 0.063 microgram/ml and 4 micrograms/ml in 1998, however, those were 0.125 microgram/ml or below in all H. influenzae in 1999 showing the strongest activity. Tobramycin and ciprofloxacin showed strong activities against P. aeruginosa (both mucoid and non-mucoid) with MIC80s of 1 microgram/ml. Number of isolated P. aeruginosa (mucoid) was little as 11, however, the susceptibilities to all drugs were better than P. aeruginosa (non-mucoid). K. pneumoniae showed good susceptibilities to all drugs except for ampicillin with decreasing of low-sensitive strains compared to those detected in 1998. Also, all drugs generally showed strong activities against M. (B.) catarrhalis. MIC80s of all drugs were 2 micrograms/ml or below. The drug which showed the strongest activity was imipenem inhibiting all 41 strains with MIC of 0.063 microgram/ml. On the patients' characteristics, the number of patients aged 80 years or older who had been increased was decreased in 1999 in the distribution by age. The percentage of the elderly patients aged 70 years or older was 47.0%, which occupied almost a half number of the total patients as in the last year. As for the incidence by disease, bacterial pneumonia and chronic bronchitis were the highest. They were noted in 37.9% and 30.5% of the patients, respectively. In 1999, bronchial asthma was frequently observed as compared in recent years. It was noted in about 10% of the patients which is the same % as in bronchiectasis. We examined the number of strains from these patients with infections before and after administration of antibiotics. In patients with bacterial pneumonia, the number of isolated strains was almost the same between those before and after administration. However, in patients with chronic bronchitis, the number of strains remarkably decreased to less than the half of the total after administration of antibiotics in the last year, but it decreased to 2/3 of the total in 1999. On the administration of antibiotics and isolated bacteria by the day of administration, the bacteria which were isolated more before administration were H. influenzae in 28.4%, S. pneumoniae in 25.7%, M. (B.) catarrhalis in 12.0% and S. aureus in 10.6%. The frequency of S. aureus after administration over 15 days was almost the same as that before administration, but the frequency of P. aeruginosa (both mucoid and non-mucoid) was 36.8% which was higher than that before administration. The frequency of isolated S. pneumoniae was decreased after administration and none of them was isolated after completion of administration. However, that of H. influenzae was decreased to 7.1% after administration within 3 days, and many H. influenzae were isolated after completion of administration as 21.4%.

Adolescent↗
PubMed2001

Laparoscopic detection of sentinel lymph nodes in gastrointestinal cancer: a novel and minimally invasive approach.

Although the sentinel node (SN) concept has been validated in malignant melanoma and breast cancer, the application of this concept for other solid tumors, including gastrointestinal (GI) cancer, is still controversial. We have demonstrated the feasibility of radioguided SN mapping during laparotomy in patients with esophageal, gastric, and colorectal cancers. In 188 patients, the SNs identified by this technique had an overall diagnostic accuracy of 96% for regional lymph node metastasis. Aberrant drainage sites that have been called skip metastasis from the primary lesion were detectable using this method. More recently, we have undertaken SN mapping during laparoscopic surgery. A combination of radiotracer and blue dye optimized the identification of SNs that drained GI cancers. Our preliminary data indicate that laparoscopic mapping of the SN is a sensitive intraoperative technique for identifying lymph node micrometastasis, and we believe that it will become an important component of a minimally invasive approach to early-stage GI cancers.

Colonic Neoplasms↗
PubMed2000

Oxidized low-density lipoprotein impairs the anti-coagulant function of tissue-factor-pathway inhibitor through oxidative modification by its high association and accelerated degradation in cultured human endothelial cells.

We have examined whether oxidized low-density lipoprotein (ox-LDL) affects the function of tissue-factor-pathway inhibitor (TFPI), an anti-coagulant regulator in the extrinsic pathway of coagulation, in cultured human umbilical vein endothelial cells (HUVEC). Treatment of culture medium of HUVEC with ox-LDL, but not with native or acetylated LDLs, drastically decreased the reactivity of TFPI to its antibody specific for Kunitz domain 1 or one specific for the conformation between Kunitz 1 and 2 of TFPI, and caused a rapid, concentration-dependent decrease in the functional activity of TFPI to inhibit Factor X activation. When 5 ng of recombinant TFPI (rTFPI) was mixed with 10 microg of ox-LDL for 30 min, almost all of the rTFPI was detected in the ox-LDL fraction and no free rTFPI was observed on non-denaturing PAGE, in contrast with the virtual absence of rTFPI in the native LDL fraction. Ox-LDL decreased the antigen level of TFPI in the lysate of HUVEC in a time-dependent manner. It did not affect the mRNA level, but ox-LDL-dependent reduction of the TFPI antigen level in HUVEC was reversed by the simultaneous treatment of ox-LDL with bafilomycin A1, an inhibitor of the lysosomal proton pump. These results indicate that ox-LDL lessens the anti-coagulant function of TFPI through both oxidative modification and accelerated degradation of the molecule outside and inside HUVEC respectively.

Anticoagulants↗
PubMed2000

Acceleration of thrombomodulin gene transcription by retinoic acid: retinoic acid receptors and Sp1 regulate the promoter activity through interactions with two different sequences in the 5'-flanking region of human gene.

The interactions between retinoic acid- (RA)-dependent transcriptional regulatory sequences of the 5'-untranslated region of the thrombomodulin gene and nuclear RA-responsive proteins were studied using human pancreas BxPC-3 cells. Deletion mutants of pTM-CAT plasmid revealed the presence of distal and proximal RA-responsive regions containing direct repeat with 4 spaces (DR4) and three of four Sp1 sites, respectively. Cotransfection of a pTM-CAT plasmid with expression plasmids of RA receptors (RARalpha, RARbeta, and RARgamma) augmented the promoter activity under the condition of lower retinoid X receptor-alpha (RXRalpha) expression, whereas the activity was greatly diminished when RXRalpha was highly expressed. An electrophoretic mobility shift assay with cDNA containing the DR4 indicated that heterodimers of RAR and RXRalpha interacted with the DR4 site, although the interaction gradually disappeared with the increase in the ratio of RXRalpha/RAR. On the other hand, Sp1 protein interacted especially with the tandem Sp1 site corresponding to the first and second Sp1 sequences of the four Sp1 sites in the proximal RA-responsive region. The binding of Sp1 to Sp1 sites was independent of RAR-RXR heterodimer but increased with the increase in Sp1 concentration in the presence of unknown factor(s) of reticulocyte lysate. Upon treatment of the cells with RA, time-dependent increases in the ratio of RARbeta to RXRalpha and the phosphorylated form of Sp1 were observed. We concluded that two genomic DNA regions, the DR4 site (-1531 to -1516) and the first and second Sp1-binding sites (-145 to -121), were involved in the RA-dependent augmentation of thrombomodulin gene expression through increased interactions of the two regions with heterodimer of RAR-RXRalpha and nuclear Sp1, respectively.

Binding Sites↗
PubMed2000

Ras mediates effector pathways responsible for pre-B cell survival, which is essential for the developmental progression to the late pre-B cell stage.

Ras is essential for the transition from early B cell precursors to the pro-B stage, and is considered to be involved in the signal cascade mediated by pre-B cell antigen receptors. To examine the role of p21(ras) in the late stage of B cell differentiation, we established transgenic mice (TG) expressing a dominant-inhibitory mutant of Ha-ras (Asn-17 Ha-ras) in B lineage cells at high levels after the early B cell precursor stage. Expression of p21(Asn-17) (Ha-ras) was associated with a prominent reduction in the number of late pre-B cells, but had little effect on proliferation of early pre-B cells. Inhibition of p21(ras) activity markedly reduced the life span of pre-B cells, due, at least in part, to downregulation of the expression of an antiapoptotic protein, Bcl-xL. Thus, the apparent role for p21(ras) activity in pre-B cell survival may explain the decreased numbers of late pre-B cells in Asn-17 Ha-ras TG. Consistent with this possibility, overexpression of Bcl-2 in Asn-17 Ha-ras TG reversed the reduction in the number of late pre-B cells undergoing immunoglobulin light chain gene (IgL) rearrangement and progressing to immature B cells. These results suggest that p21(ras) mediates effector pathways responsible for pre-B cell survival, which is essential for progression to the late pre-B and immature B stages.

Animals↗
PubMed2000

Membrane lymphotoxin is required for the development of different subpopulations of NK T cells.

The development of lymphoid organs requires membrane-bound lymphotoxin (LT), a heterotrimer containing LTalpha and LTbeta, but the effects of LT on T cell function have not been characterized extensively. Upon TCR cross-linking in vitro, splenocytes from both LTalpha-/- and LTbeta-/- mice failed to produce IL-4 and IL-10 due to a reduction in NK T cells. Concordantly, LTalpha-/- and LTbeta-/- mice did not respond to the lipoglycan alpha-galactosylceramide, which is presented by mouse CD1 to Valpha14+ NK T cells. Interestingly, both populations of NK T cells, including those that are mouse CD1 dependent and alpha-galactosylceramide reactive and those that are not, were affected by disruption of the LTalpha and LTbeta genes. NK T cells were not affected, however, in transgenic mice in which LT signaling is blocked, beginning on day 3 after birth, by expression of a soluble decoy LTbeta receptor. This suggests that membrane-bound LT is critical for NK T cells early in ontogeny, but not for the homeostasis of mature cells.

Animals↗